The present invention relates to surgical cuffs of the type used for forming a fluid-tight connection to a blood vessel in the body of a human or animal subject. In particular, it relates to cuffs which are sutured to a major vessel and/or to tissue surrounding the vessel in order to establish a connection for a blood pumping mechanism such as a total artificial heart (TAH). One such structure, having a fabric suture ring attached to a stent which supports a valved flow tube, is shown in U.S. patent application Ser. No. 720,361 filed Apr. 5, 1985 of inventors David M. Lederman et al. Reference is made to that application for specific descriptions of material coatings and surface properties.
Atrial cuffs and vascular graft connector junctions, as well as mountings for valves which may be included in such structures, have been identified as primary locii for thrombus formation. This is due to many factors, including the surrounding fluid flow conditions, physical gaps and irregularities in the structures, and also the biocompatibility surface properties of the materials employed in such structures. In addition, occlusion of inflow openings of artificial heart devices has been observed due to pannus formation extending up to and into the openings.
The foregoing problems have been addressed by several approaches, including the precision formation of mating structural elements to eliminate gaps; the micro-finishing of exposed surfaces to discourage microembolus formation, and the selection of appropriately biocompatible materials. Nonetheless thrombogenesis, thromboembolism and device flow obstruction remain as major potential problems in heart device surgery.